Intelligent energy selection and asymmetric propagation of electromagnetic wave realized by composite metamaterials

In this paper, a composite metamaterial structure which can realize both energy shielding for high power electromagnetic wave (HPEW) using PIN diodes and asymmetric propagation for small communication signals is proposed. The whole structure consists of an energy selective surface (ESS), a 90° polarization converter, and a polarization-sensitive absorber which absorbs the y-polarized wave. In the normal case, signals containing rather low energy are incident on the surface of ESS, which is not powerful enough to make diodes work, so the structure is transparent to the incident wave and can realize asymmetric transmission at 3.21GHz. On the contrary, when the structure is exposed to HPEW, the rapidly increased electric field and magnetic field trigger the ESS and the incident HPEW is reflected. This kind of structure may have many potential applications on cloaking in-band for the antenna and shielding high power wave at the same time.